﻿using System;
/*
基类的初始化

派生类继承了基类的成员变量和成员方法。因此父类对象应在子类对象创建之前被创建。您可以在成员初始化列表中进行父类的初始化。
 */
namespace RectangleApplication
{
    class Rectangle
    {
        // 成员变量
        protected double length;
        protected double width;

        public Rectangle(double l, double w)
        {
            length = l;
            width = w;
        }

        public double GetArea()
        {
            return length * width;
        }

        public void Display()
        {
            Console.WriteLine("长度：{0}", length);
            Console.WriteLine("宽度：{0}", width);
            Console.WriteLine("面积：{0}", GetArea());
        }
    } // end class Rectangle

    class Tabletop : Rectangle
    {
        private double cost;

        public Tabletop(double l, double w) : base(l, w)
        {

        }

        public double GetCost()
        {
            double cost;
            cost = GetArea() * 70;
            return cost;
        }

        public void Display()
        {
            base.Display();
            Console.WriteLine("成本：{0}", GetCost());
        }
    }

    class ExecuteRectangle
    {
        static void Main(string[] args)
        {
            Tabletop t = new Tabletop(4.5, 7.5);
            t.Display();
            Console.ReadLine();
        }
    }
}